Miniature hearing instrument configured for positioning at least partially in bony region of ear canal

ABSTRACT

The application relates to a portable electronic device comprising a) a folded substrate carrying components of the device, and b) another, separate component having a fixed outer contour, and c) a housing for enclosing said folded substrate and said separate component, said housing having an inner contour, wherein said folded substrate is folded from a planar substrate along a folding line, said folded substrate exhibiting outer edges comprising a folded edge following said folding line. The application further relates to a method of manufacturing a folded substrate. The object of the present application is to facilitate miniaturization of a portable electronic device, such as a hearing aid. The problem is solved in that the folded substrate is shaped to provide that at least one of said outer edges follow(s) the fixed outer contour of the separate component and/or the inner contour of said housing. This has the advantage of providing a larger area on the substrate to place components and soldering points thereby improving the use of the available space in the portable electronic device. The invention may e.g. be used in electronic devices where volume utilization is an important design parameter, e.g. hearing aids comprising a part adapted for being mounted in an ear canal of a user, e.g. in the bony part of the ear canal.

This application is a Divisional of application Ser. No. 15/824,043,filed on Nov. 28, 2017, which is a Continuation of application Ser. No.15/092,016, filed on Apr. 6, 2016, now U.S. Pat. No. 9,866,977, issuedon Jan. 9, 2018, which is a Divisional of application Ser. No.13/154,676, filed on Jun. 7, 2011, now U.S. Pat. No. 9,338,569, issuedon May 10, 2016, which claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Application No. 61/351,949, filed on Jun. 7, 2010, and under35 U.S.C. § 119(a) to Application No. EP 10165072.9, filed in Europe onJun. 7, 2010, all of which are hereby expressly incorporated byreference into the present application.

TECHNICAL FIELD

The present application relates to portable electronic devices, e.g.hearing aids, e.g. such hearing aids that are adapted to be located inthe ear canal of a user. The disclosure relates specifically to aportable electronic device comprising a) a folded substrate carryingcomponents of the device, and b) another, separate component having afixed outer contour, and c) a housing for enclosing said foldedsubstrate and said separate component, said housing having an innercontour, wherein said folded substrate is folded from a planar substratealong a folding line, said folded substrate exhibiting outer edgescomprising a folded edge following said folding line.

The application furthermore relates to a method of manufacturing afolded substrate for a portable electronic device.

The disclosure may e.g. be useful in applications such as electronicdevices where volume utilization is an important design parameter, e.g.hearing aids comprising a part adapted for being mounted in an ear canalof a user, e.g. in the bony part of the ear canal.

BACKGROUND ART

The following account of the prior art relates to one of the areas ofapplication of the present application, hearing aids.

Space is a scarce resource in a hearing aid. The smaller the hearingaid, the more of the design focus is associated with overcoming volumerestraints. An example of a device where such considerations areextremely important is a hearing aid comprising a part adapted for beingworn in the bony part of the ear canal (a so-called deep in the earcanal type hearing aid).

US 2008/0137891 A1 describes a deep in the ear hearing aid comprising amicrophone, a speaker and an amplifier, as well as a battery connectedto an electronics part, wherein the battery accommodation is arranged onthe microphone side and comprises a sleeve connected to the electronicspart, of which the first end pointing away from the electronics part isopen for taking said battery and for providing a sound inlet in thespace between said sleeve and the battery fitted therein. The sleeve hasan open end and a closed end.

U.S. Pat. No. 6,208,741 describes a battery enclosure for miniaturehearing devices that are deeply and entirely positioned within the earcanal of an individual. The battery enclosure is a thin encapsulationthat is formed or fitted directly over the battery thus substantiallyassuming the shape of the encapsulated battery. In an embodiment, thebattery enclosure is coated over the battery with protruding contactsforming a battery assembly ready for electrical connection to aminiature canal hearing device.

WO 00/25551 A1 describes a hearing aid with a housing formed with anexterior peripheral layer of a deformable material. Electroniccomponents located within the deformable layer can be encapsulated, atleast in part, with a second deformable material. The second materialalso fills voids in the interior of the deformable peripheral layer.

U.S. Pat. No. 6,751,327 describes a battery assembly comprising anelongated plastic shell irregularly shaped to fit optimally inanatomical cavities, particularly ear canals. The battery assemblyrelies structurally on a thin plastic shell which is designed to beinexpensively formed in a variety of complex shapes, thus offeringsuperior volumetric utilization and energy capacity when compared withconventional metal button cell designs.

DISCLOSURE OF INVENTION

An aspect of the idea is to shape a flexible substrate carrying at leastsome of the electronic components of the portable electronic device tofit the battery form (and/or to the form of another relatively largecomponent located external to the substrate and/or to the inner contouror shape of the housing) in a three dimensional structure.

An object of the present application is to facilitate miniaturization ofa portable electronic device, such as a hearing aid.

Objects of the application are achieved by the invention described inthe accompanying claims and as described in the following.

A portable electronic device:

An object of the application is achieved by a portable electronic devicecomprising a) a folded substrate carrying components of the device, andb) another, separate component having a fixed outer contour, and c) ahousing for enclosing said folded substrate and said separate component,said housing having an inner contour, wherein said folded substrate isfolded from a planar substrate along a folding line, said foldedsubstrate exhibiting outer edges comprising a folded edge following saidfolding line. The portable electronic device is characterized in thatthe folded substrate has a shape to provide that at least one of saidouter edges follow(s) the fixed outer contour of the separate componentand possibly the inner contour of said housing.

This has the advantage of providing a larger area on the substrate toplace components and soldering points thereby improving the use of theavailable space in the portable electronic device.

A portable electronic device is in the present context taken to mean anelectronic device (which at least during operation is) adapted for beingworn by a person, e.g. at or in an ear, around an arm, around the neck,in a pocket or attached to a piece of clothing, e.g. a belt. Typically,a portable electronic device comprises a local energy source (e.g. a(possibly rechargeable) battery) for energizing the electroniccomponents of the device. In an embodiment, the portable electronicdevice comprises an electric interface (e.g. a wired or wireless) toanother device or a network. In an embodiment, portable electronicdevice is a relatively small device, e.g. having maximum outerdimensions smaller than 0.1 m, such as smaller than 0.05 m, such assmaller than 0.02 m, such as smaller than 0.01 m.

In an embodiment, the portable electronic device comprises a CIC-part(CIC=Completely In the ear Canal) adapted for being mounted in the earcanal of the user wherein the CIC part comprises said housing and saidfolded substrate and said separate component. In an embodiment, theCIC-part is adapted for being mounted deep in the ear canal. In anembodiment, the CIC-part is adapted for being mounted fully or partiallyin the bony part of the ear canal.

In an embodiment, the portable electronic device comprises a signalprocessing unit for enhancing the input signals (e.g. providing afrequency dependent gain to compensate for a hearing loss of a user) andproviding a processed output signal. In an embodiment, the portableelectronic device comprises a listening device, such as a hearinginstrument (e.g. a deep in the ear canal type hearing instrument adaptedfor being mounted fully or partially in the bony part of the ear canal),a headset, a headphone or an active ear protection device or acombination thereof.

In an embodiment, the portable electronic device comprises an outputtransducer for converting an electric signal to a stimulus perceived bythe user as an acoustic signal. In an embodiment, the output transducercomprises a number of electrodes of a cochlear implant or a vibrator ofa bone conducting hearing device. In a preferred embodiment, the outputtransducer comprises a receiver (speaker) for providing the stimulus asan acoustic signal to the user.

In an embodiment, the portable electronic device comprises a transceiverunit for receiving (and/or transmitting) a direct electric input. Thetransceiver unit may be a wireless transceiver unit comprising antenna,transmitter and/or receiver and modulation and/or demodulationcircuitry.

In an embodiment, the housing has a fixed inner and outer outline orform (in the meaning that a standard housing is used for a larger numberof devices).

In an embodiment, the housing of (or a part thereof) has a variableinner and/or outer outline or form (in the meaning that a non-standardhousing is used, e.g. custom made to each product, or made in a numberof variants).

The term ‘a folded substrate’ is in the present context taken to mean afolded planar substrate (i.e. the folded substrate is folded from aformed planar structure along a folding line). The planar substrate hasa planar (e.g. layered) structure in that it has outer, substantiallyco-planar surfaces, the planar structure being characterized in that its(thickness) dimension perpendicular to the co-planar surfaces is muchsmaller (e.g. at least 2-5 times smaller) than its extension in adirection (such as any direction) of the co-planar surfaces. The foldedsubstrate is typically folded once along a folding line to provide astructure where two parts of one of the co-planar surfaces of the planarsubstrate end op forming opposing surfaces. Thus, the folded substratetypically exhibits at least one linear edge (namely the edge thatfollows the folding line, the ‘folded edge’). The folded substratecomprises first and second folded parts (said parts being respectiveparts of the folded substrate ‘separated’ by a folding line). In anembodiment, the folded substrate comprises at least one (such as two ormore) electrical conductor(s) connecting the first and second parts. Inan embodiment, a folding zone of the folded substrate extends to eachside of the folding line and comprises the part of the folded substratethat is affected by the folding (e.g. in that it forms part of thecurved part of the folded substrate to each side of the folding line).In an embodiment, the planar substrate is adapted to provide that thefolded substrate comprises at least one (such as two or more) electricalconductor(s) connecting the first and second parts via the folding zone.In an embodiment, the first and second folded parts are of substantiallyequal form and area to (when folded along the folding line by a foldingangle of 180°) provide a folded substrate having a sandwich structurecomprising (at least) two opposing parts of the planar substrate ofsubstantially identical form and area. In an embodiment, the formedplanar substrate (before folding) comprises 1^(st) and 2^(nd) partsextending to respective sides of, e.g. symmetrically around, the foldingline. This need, however, not be the case, and is basically a systemdesign option. In an embodiment, the first and second (folded) parts areof different form and area.

In an embodiment, the folded substrate comprises more than one fold,e.g. two folds to provide a folded substrate comprising three of morelayer parts of the planar substrate (or to provide a folded substratecomprising one or more asymmetric extensions from one or more edges ofthe substrate parts), the folding of a third part being e.g. in anopposite direction of the folding of first and second parts. Typically,the planar substrate is folded along the folding line by a folding angleof 180°. In an embodiment, the folding angle is smaller than 180°, e.g.smaller than 160° to allow room between the folded parts of the planarstructure, e.g. for larger components mounted on the planar structure orto allow components external to the substrate to extend in between thefolded parts. In an embodiment, the folded substrate comprises two ormore folds (e.g. three folds), e.g. to provide a resulting foldedsubstrate having parallel parts with a distance between opposingsurfaces of the parallel parts allowing larger components to be mountedon one or both of said opposing surfaces or allowing components externalto the substrate to extend in between the folded parts. In anembodiment, a folding angle of a folding line of an extension from anedge of the substrate a substrate part is in the range between 0° and180°, e.g. in a range including 90°.

In an embodiment, the planar substrate is folded along the (primary)folding line to provide that the folding radius is larger than or equalto a critical folding radius for said planar substrate or for the partof the substrate within a folding zone comprising the folding line. Inan embodiment, the folding radius of the folded substrate is larger thanor equal to half the distance between opposing surfaces of the foldedparts of the substrate (thereby creating a semicircular cross section ofthe folding zone perpendicular to the planar substrate (of the foldedsubstrate) including a circle section spanning more than 180°, at leastone of the folded pars being folded along a auxiliary folding linerunning parallel to the primary folding line, the fold along theauxiliary folding line(s) being in opposite direction(s) of the foldalong the primary folding line). In an embodiment, a folding zoneextends in both directions perpendicular to the folding line a distancelarger than or equal to the folding radius (when viewed on theun-folded, planar substrate).

In an embodiment, the planar substrate is adapted to have a certaingeneral critical folding radius and a smaller critical folding radius ina folding zone around said folding line. The critical folding radius ofa planar substrate is in the present context taken to mean the smallestradius by which the substrate can be folded to provide a foldedsubstrate folded 180° along a folding line without damaging thefunctional structures (e.g. printed conductors) on the surface of orembedded in the planar substrate.

In an embodiment, the planar substrate has a certain general thicknessand a smaller thickness in a folding zone around said folding line toprovide a decreased critical folding radius of the substrate in saidfolding zone compared to a critical folding radius for the substrate ingeneral.

In an embodiment, at least one of the outer edges following the fixedouter contour of the separate component and/or the inner contour of saidhousing comprises an outer edge other than said folded edge.

In an embodiment, the shaping of the at least one of said outer edgescomprise(s) providing an outer form comprising piece-wise linear parts.In an embodiment, the shaping of the at least one of said outer edgescomprise(s) providing an outer form comprising non-linear, e.g.elliptical, parts (an edge between two vertices following a non-linearpath, e.g. describing a part of a circle or an ellipse or any other,preferably relatively smooth, (non-linear) curve). In an embodiment, theoutline of the folded substrate when viewed in a top view (perpendicularto the planar substrate or to one of the folded parts) has anon-rectangular form. In an embodiment, the shaping of the at least oneof said outer edges results in the folded substrate to comprise one ormore straight line or non-linear edges, e.g. an edge comprising a partof an ellipse. In an embodiment, at least one of the straight line ornon-linear edges meet (intersect) another edge in a physical or virtualvertex (a virtual vertex being e.g. formed by extensions of the edges inquestion, but lying outside the substrate) under an angle different from90°, e.g. at least 10° different from 90°, e.g. in a range from 20° to80°.

In an embodiment, the planar substrate is adapted to allow the mountingof components on both sides of the substrate. In an embodiment, theplanar substrate is a multi-layer substrate adapted for having more thanone layer of electric conductors to provide electrical connection tocomponents on the substrate and/or to components external to thesubstrate. In an embodiment, the planar substrate comprises intermediatelayers adapted for routing metallic conductors to connect to conductorsin other intermediate layers and/or to the surface(s) of the substrate.

In an embodiment, the folded substrate comprises one or more distancekeeping components adapted for ensuring a minimum distance betweenopposing surfaces of the folded substrate. In an embodiment, a distancekeeping component comprises a locking mechanism for locking two ends ofa finalized folded substrate. This has the advantage of easing handlingof the folded substrate during manufacturing of the device. In anembodiment, a distance keeping component is located in a part of thesubstrate where no other components are easily mounted (e.g. in a wedgeformed part of the substrate).

In an embodiment, the planar substrate—e.g. a printed circuit board(PCB) (e.g. a flexible PCB)—is adapted to provide that electroniccomponents can be mounted directly onto one or both sides of the planarsubstrate using a Surface Mount Technology (SMT) (as opposed to mountingtechnologies e.g. involving pins extending through holes in the planarsubstrate). Components that are specifically adapted for being surfacemounted are typically physically smaller than corresponding componentswith pins. The use of surface mount components is in general anadvantage where relatively small dimensions and a relatively high degreeof automation in the mounting process is an advantage. Electroniccomponents adapted for being surface mount are often referred to as SMD(Surface Mount Device) components. An SMD component has electricalterminals in the form of metallised areas (e.g. in the form of end caps)suitable for being soldered (typically by a machine) directly ontosolderable electrically conducting pads on the surface of a substrateprovided with solder paste for receiving a particular SMD component (theplanar substrate, e.g. a PCB, typically having predefined electricallyconducting patterns for interconnecting the various SMD components (andpossible other electronic components) on the substrate and possibly forconnecting the circuitry to external parts).

In an embodiment, the folded substrate comprises one or more extensionsadapted for electrically connecting components on the folded substrateto components (e.g. a battery or a microphone unit or a speaker unit)external to the folded substrate. In an embodiment, such extensionextends from an edge of one of the parts of the folded substrate otherthan the folded edge. In an embodiment, a given extension extending froman edge of a first part of the folded substrate is NOT replicated in theother part of the substrate, so that a given extension extending from anedge of a first part of the folded substrate does not have a mirrorimage (around a plane through the folding line and parallel to a surfaceof the first part of the folded substrate) extending from an edge of asecond part of the folded substrate. In other words, the first andsecond parts of the folded substrate are, in such embodiment, not mirrorsymmetric around a centrally located, intermediate plane between the twoparts in a folded state (nor symmetric around a folding line when viewedin a formed planar (un-folded) state). In an embodiment, the foldedsubstrate comprises one of more symmetric extensions. In an embodiment,the extensions are adapted to establish electrical connection to anexternal component, e.g. a battery. In an embodiment, extensions of thefolded substrate are adapted to press against a housing of an externalcomponent, when in a (final) folded state. This provides an easyelectric connection of the external component, e.g. a battery, toelectrical components of the folded substrate. In an embodiment, theextension(s) comprise electrical connections, e.g. soldering pads (e.g.comprising solder paste) or electrically conducting tape, which areprepared for soldering or otherwise fixing the extensions of the foldedsubstrate to the external component (e.g. to allow reflow soldering ordirect gluing of the external component to the extensions of the foldedsubstrate).

A Method of Manufacturing a Folded Substrate:

A method of manufacturing a folded substrate for a portable electronicdevice described above, in the detailed description of ‘mode(s) forcarrying out the invention’ and in the claims is furthermore provided bythe present application. The method comprises

a) Deciding an outer form of the folded substrate;

b) Determining a folding line;

c) Providing a planar substrate having a critical folding radius along afolding line;

d) Extracting the outer outline of a planar substrate considering theouter form of the folded substrate, the folding line and a predeterminedfolding radius larger than or equal to the critical folding radius alongthe folding line of the substrate;

e) Drafting a layout of components and electrical connections to beincluded on the planar substrate;

f) Providing a planar substrate comprising a footprint of the electricalconnections determined in step e);

g) Mounting the components on the planar substrate;

h) Providing a formed planar substrate having the outer outlineextracted in step d);

i) Folding the substrate along the folding line with the predeterminedfolding radius.

It is intended that the structural features of the portable electronicdevice described above, in the detailed description of ‘mode(s) forcarrying out the invention’ and in the claims can be combined with themethod, when appropriately substituted by a corresponding process andvice versa. Embodiments of the method have the same advantages as thecorresponding portable electronic device.

In the system design of the portable electronic device, it isanticipated that the device comprises a folded substrate containing (atleast some, e.g. all, of the) electronic components of the device andtheir interconnections. Step a) of deciding an outer form of the foldedsubstrate can e.g. be based on a system design layout comprising adescription of the basic components of the device in question includingthe external and internal form and size of its housing and a partitionof the system into components to be included on a substrate and separatecomponents and their location and interconnections. Such system designcan e.g. be made using a computer aided drawing tool, e.g. AutoCAD™ (ofAutodesk Inc., USA) or Pro/Engineer® (of Parametric TechnologyCorporation, USA).

Step b) of determining a folding line can e.g. be decided on from apractical view of the system design layout considering e.g. the locationof internal (i.e. on the substrate) and external components andelectrical connection points (e.g. solder pads) for external components,ease of manufacture and reliability of the folded substrate. Preferably,the edge of the folded substrate (‘the folded edge’) containing thefolding line is NOT one of the edges that is shaped to follow the fixedouter contour of the separate component and/or the inner contour of thehousing, if this contour is non-linear).

Step c) of providing a planar substrate having a critical folding radiusalong a folding line may in an embodiment, comprise c1) providing afolding zone to the planar substrate extending to each side of thefolding line. In an embodiment, step c1) comprises arranging that theplanar substrate has a smaller critical folding radius in the foldingzone than outside the folding zone. Alternatively, step c1) may beincluded in step f) of providing a planar substrate comprising afootprint of the electrical connections determined in step e).

Step d) of extracting the outer outline of a planar substrateconsidering the outer form of the folded substrate, the folding line anda predetermined folding radius larger than or equal to the criticalfolding radius along the folding line of the substrate can e.g. be madeon a trial and error basis, e.g. using physical models (e.g. making amodel of the folded substrate using an appropriate folded sheet that caneasily be formed to the actual needs, e.g. a sheet of paper or plasticfoil and a cutting tool, e.g. a pair of scissors), or alternativelyusing a computer aided design tool (e.g. e.g. 3D design softwareSolidWorks Premium® (from Solid Works Corp., USA) or Pro/Engineer® (ofParametric Technology Corporation, USA) with a feature implementing theso-called ‘sheet metal method’).

Step e) of drafting a layout of components and electrical connections tobe included on the planar substrate can e.g. be based on a system designlayout comprising a description of the basic components (including thefolded substrate) of the device in question as used in step a) and onthe outer outline of the planar substrate extracted in step d). A layoutof components and electrical connections can e.g. be made using acomputer aided design tool (e.g. a dedicated PCB-design tool, such ase.g. PADS® (from Mentor Graphics, USA) or Cadence Allegro® (from CadenceDesign Systems, Inc., USA) or a mixed mechanical and electrical designtool, e.g. Pro/Engineer® (of Parametric Technology Corporation, USA)).

Step f) of providing a planar substrate comprising a footprint of theelectrical connections determined in step e) may comprise any planarprocessing technology for providing a substrate for mounting andinterconnecting electronic components. One example is PCB technologywherein electrical connections (the footprint) are applied to a planardielectric material in a multistep planar process (e.g. amask-deposit-etch process as is known from semiconductor technology).The substrate may e.g. be a multilayer substrate (e.g. a flexiblesubstrate, e.g. made of a plastic polymer, e.g. PET (PolyEthyleneTerephthalate) or PEN (PolyEthylene Naphthalate) or epoxy glass) and/orboth sides of the substrate may be used to mount components and/or routeelectrical connections. In an embodiment, step f) comprises the creationof a cutting line or cutting profile along the outer outline of theplanar substrate as determined in step d) to facilitate the laterprovision of a formed planar substrate in step h). In an embodiment, theelectrical connections comprise wires of a single or of different widthsfor connecting components on the substrate and/or to connection pointsto external components (e.g. located on extensions to the foldedsubstrate). In an embodiment, the electrical connections comprise padsfor electrically connecting to components external to the planarsubstrate. In an embodiment, the pads are placed in the layout in partsof the planar substrate that is otherwise difficult to utilize, e.g. dueto its irregular form and/or small area, e.g. in parts of the substratewhose edges meet at a mutual angle smaller than 90°, such as smallerthan 60°, such as smaller than 45°.

Step g) of mounting the components on the planar substrate may e.g. beperformed manually or using an automated process, e.g. using SMDtechnology.

Step h) of providing a formed planar substrate having the outer outlineextracted in step d) (shaping) may in an embodiment comprise sawing orcutting (e.g. using a laser) out the extracted form from a sheet ofplanar substrate comprising the footprint (e.g. comprising a multitudeof identical layouts).

Step i) of folding the substrate along the folding line with thepredetermined folding radius may be performed in a manual or anautomated process to provide a folded substrate folded along the foldingline with a predefined folding angle (e.g. 180°).

The method rents itself conveniently to produce a multitude of formedplanar substrates (and from them a multitude of folded substrates) froma single planar ‘sheet’ substrate. In an embodiment, the methodcomprises providing a multitude of folded substrates by

-   -   in step f) providing a planar substrate comprising a multitude        of layouts, each having a footprint of the electrical        connections determined in step e); and    -   in step g) mounting components for the multitude of layouts on        the planar substrate;    -   in step h) providing a multitude of formed planar substrates        each having the form extracted in step d) and comprising the        components mounted in step g); and    -   in step i) folding said multitude of individual formed planar        substrates along the folding line with the predetermined folding        radius.

This has the advantage of providing a multitude of folded substrates(including mounted components) in a batch type (fully or partiallyautomated) process.

Further objects of the application are achieved by the embodimentsdefined in the dependent claims and in the detailed description of theinvention.

As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well (i.e. to have the meaning “at leastone”), unless expressly stated otherwise. It will be further understoodthat the terms “includes,” “comprises,” “including,” and/or“comprising,” when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof. It will be understood that when an element isreferred to as being “connected” or “coupled” to another element, it canbe directly connected or coupled to the other element or interveningelements maybe present, unless expressly stated otherwise. Furthermore,“connected” or “coupled” as used herein may include wirelessly connectedor coupled. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items. The steps ofany method disclosed herein do not have to be performed in the exactorder disclosed, unless expressly stated otherwise.

BRIEF DESCRIPTION OF DRAWINGS

The disclosure will be explained more fully below in connection with apreferred embodiment and with reference to the drawings in which:

FIGS. 1a-b show cross sections of two embodiments of a completely in theear canal type hearing aid comprising a battery and a folded substratefor carrying components of the hearing aid,

FIGS. 2a-e show various embodiments of a flexible planar substrate andcorresponding folded substrate for being used in embodiments of aportable electronic device,

FIGS. 3a-c show an embodiment of a folded substrate shaped to follow thefixed outer contour of a battery, substrate and battery being a part ofa portable electronic device, as e.g. illustrated in FIG. 1a (partsFolded substrate and Battery),

FIGS. 4a-b show exemplary embodiments of a planar substrate comprising a(reduced thickness) folding zone,

FIGS. 5a-b show an embodiment of a completely in the ear canal typehearing instrument, and

FIGS. 6a-b show two mutually perpendicular views of an embodiment of afolded substrate according to the present disclosure.

The figures are schematic and simplified for clarity, and they just showdetails which are essential to the understanding of the disclosure,while other details are left out.

Further scope of applicability of the present disclosure will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the disclosure, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the disclosure will becomeapparent to those skilled in the art from this detailed description.

MODE(S) FOR CARRYING OUT THE INVENTION

FIGS. 1a-b show cross sections of two embodiments of a completely in theear canal type hearing aid comprising a battery and a folded substratefor carrying components of the hearing aid. The embodiments of a hearingaid in FIGS. 1 a-b comprise a Housing enclosing a Folded substratecomprising a number of interconnected electronic components including aLoudspeaker (receiver) unit for presenting an acoustic output signal touser via a Loudspeaker outlet attached to or forming part of a flexibleDome element for locating the hearing aid in an ear canal of a user. Inpractice, other components (e.g. discrete or integrated circuitcomponents) in addition to the Loudspeaker (receiver) unit are typicallylocated on the Folded substrate. The Housing further encloses a Batteryfor energizing the components of the hearing aid enclosed in the Housingand a Microphone unit for picking up a sound from the environment via aMicrophone inlet. The Microphone unit, the Battery and the Loudspeaker(receiver) unit are electrically connected to the folded substrate viaconnecting wires and Solder contacts on the substrate. A Folding zone (apart of the planar substrate mechanically affected by the folding, e.g.by contributing to the curvature) is indicated on the folded substrate.The Folding zone is limited by the dashed line and the nearest outerboundary (the Folding zone typically running on both parts of the planarsubstrate symmetrically around a folding line represented by the outeroutline of the folded substrate next to the dashed line, as e.g.illustrated in FIGS. 5a-b and 6a-b ). In the embodiment of FIG. 1a , theouter edges of the Folded substrate are shaped to follow the outer formof the Battery AND the inner form of the Housing, thereby utilizing theavailable space in the Housing (the Folded substrate having asubstantially polygonal form comprising 6 vertices, all but oneconnected by straight line edges, the last containing a curved shapefollowing the outer form (here a part of a circle) of the Battery, cf.e.g. FIG. 2a ). The embodiment shown in FIG. 1b is similar to that ofFIG. 1a but differs in that the outer edges of the Folded substrate areONLY adapted to the inner form of the Housing (the Folded substratehaving a polygonal form comprising 6 vertices connected by straight lineedges, cf. e.g. FIG. 2d ).

FIGS. 2a-e show various embodiments of a foldable planar substrate andcorresponding folded substrate for being used in embodiments of aportable electronic device. FIGS. 2a-e show five examples (top tobottom, FIG. 2a-2e ) of Formed planar substrates (shown to the left)having an outer outline, which when folded 180° along the Folding line(the central dash-dotted line, surrounded by two symmetrically locateddashed lines indicating the Folding zone), lead to the Folded substrate(shown to the right). The Formed planar substrate comprises 1^(st) and2^(nd) parts extending to respective sides of (here symmetricallyaround) the Folding line.

FIGS. 3a-c show an embodiment of a folded substrate shaped to follow thefixed outer contour of a battery, substrate and battery being a part ofa portable electronic device, e.g. a device as illustrated in FIG. 1a(compare parts Folded substrate and Battery in FIG. 1a ). FIG. 3a is aperspective view of the folded substrate F-SUB, where one of the edgesis adjacent to the battery and shaped as a part of a circle to fit thecircular form of a battery cell BAT. Various SMD components COMP aremounted on the folded substrate and electrically interconnected byconductors on the surface of the substrate and/or in one or moreintermediate layers of the substrate. The folded substrate comprises anextension E-SUB formed on and extending from an outer edge of one of thefolded parts of the folded substrate. As shown in FIGS. 3a-c , theextension E-SUB is formed on another outer edge of the folded substratethan the outer edge adjacent to the battery (i.e., the edge shaped aspart of a circle). The extension E-SUB of the substrate compriseselectrical conductors (CON-B+, CON-M) for connecting the components onthe folded substrate to the (positive terminal+ of the) battery BAT andto another component (here a microphone, not shown), respectively. Theelectrical connections (CON-B+, CON-M) of the extension E-SUB comprisesoldering pads or electrically conducting tape allowing (e.g. reflow)soldering or direct gluing of the battery and the microphone,respectively, to the extension E-SUB of the folded substrate F-SUB.Apart from the curved edge of the folded substrate F-SUB (forming partof a circle) facing the battery, the three other edges (one being thefolded edge) are linear.

FIGS. 3b and 3c show two different perspective views of the foldedsubstrate F-SUB (without components for clarity) including the extensionE-SUB and in particular illustrating the form of the extended substrate.As illustrated by FIGS. 3b and 3c the folded substrate F-SUB includingthe asymmetric extension of the substrate E-SUB, which is formed on andextending from an outer edge of one of the folded substrate parts, canbe created from one sheet of a planar substrate by appropriate formingand cutting and subsequent folding along the dashed folding lines (FL ofthe core folded substrate, and FL1-FL6 of the extension) indicated inFIG. 3b . Alternatively, the extension of the substrate E-SUB can beseparately provided and electrically connected (e.g. along folding lineFL1) to the (core) folded substrate F-SUB by conventional electricalconnection techniques.

FIGS. 4a-b show exemplary embodiments of a planar substrate comprising a(reduced thickness) folding zone. FIGS. 4a-b show a part of a planarsubstrate P-SUB around a folding zone F-ZONE, which has been reduced inthickness to a folded zone thickness T_(s, fold) relative to a (possiblyaverage) thickness T_(s) of the planar substrate outside the foldingzone F-ZONE. The planar substrate P-SUB is a multilayer substratecomprising a number of layers (here three intermediate layers are shown)for establishing electrical connections between components on therespective substrate parts (to the left and right sides of the foldingzone F-ZONE) and for establishing electrical contact between the twosubstrate parts (including for creating electrical contact betweencomponents located on different substrate parts) via the folding zoneF-ZONE. In the embodiment of a planar substrate shown in FIGS. 4a-b ,five layers may be used for routing of electrical conductors (two on theopposite surfaces and three intermediate layers), the conducting layers(or rather the layers that may be used for routing of electricalconductors) being separated by electrically insulating layers. However,to decrease the critical folding radius, the substrate has been thinnedin the folding zone F-ZONE by only continuing the centrally located,middle metal layer CC over the folding zone (possibly including (asshown here) surrounding insulating layers), whereas the top and bottomintermediate (conductive) layers TC and BC, respectively, arediscontinued at the folding zone. The surface layers are preferably notused for routing or contacting in the folding zone F-ZONE. In theembodiment shown in FIG. 4a , the transitions from the folding zone tothe rest of the substrate having a ‘normal’ thickness are abrupt(step-formed), whereas they are made gradual in the embodiment of FIG.4b . Further, the embodiment of FIG. 4b comprises via holes VIAconnecting two or more of the metal layers (here the three intermediatelayers are connected) in a zone close to the folding zone tomechanically stabilize the parts of the substrate neighbouring thefolding zone F-ZONE. In an embodiment, the substrate comprises a PCB,e.g. a flexible printed circuit board. Such so-called ‘flexprints’(comprising customized footprints) are available from a number ofvendors, e.g. Mekoprint Electronics A/S (of Denmark) or GS Swiss PCB AG(of Switzerland).

FIGS. 5a-b show an embodiment of a portable electronic device, here inthe form of a completely in the ear canal type hearing instrument. FIG.5a shows a cross-sectional view of the hearing instrument 5 when locatedfully in an ear canal of a user. The hearing instrument 5 is aself-contained instrument comprising microphone (M), battery (BAT)signal processing unit (SPU) and receiver (speaker, SP) (and possiblyother relevant functional parts for providing appropriate amplification(or attenuation) of an input sound and presenting it as a processedoutput sound to the residual volume 72 close to the ear drum 71according to a user's needs. The embodiment shown in FIGS. 5a-b isadapted for being located at least partially in the bony part 74 of theear canal 7. The ear canal 7 can have different lengths (and form) ondifferent people as indicated by the double arcs 76. The outer ear(pinna) is indicated with reference numeral 75. A first part of thehearing instrument 5 having a relatively small cross section is locatedat least partially in the bony part 74 of the ear canal 7. A second partof the hearing instrument 5 having a relatively large cross section islocated at least partially in the softer part 73 of the ear canal 7. Thefirst part comprises a receiver (speaker) unit SP. The second partcomprises the more voluminous components, such as e.g. a battery, asignal processing unit, a microphone system, and possible transceivercircuitry (e.g. for establishing a wireless link to another device, e.g.a corresponding hearing instrument at the opposite ear). A front end 1of the first (slim) part of the hearing instrument comprises a waxfilter 2 and an ear canal locating part 15, here a dome part, comprisingone or more structural elements for adapting its/their form to the earcanal and thereby controlling the position of the instrument (incl. thereceiver) in a cross section of the ear canal. The embodiment of thehearing instrument shown in FIGS. 5a-b comprises two vent channels 30,30′ running along a periphery (in a longitudinal direction) of thehousing 51 of the instrument comprising the electronic components (e.g.battery BAT, receiver SP, microphone and folded substrate F-SUBcomprising signal processing unit SPU and interconnection circuitry).The folded substrate comprising the (typically mainly digital) signalprocessing unit SPU and a (typically mixed analogue and digital) frontend chip FE is shaped to follow the outer surface of the battery BAT andof an inner surface of the housing 51. The hearing instrument may haveany other convenient form, and be located elsewhere in the ear canal(e.g. outside the bony part). Likewise, a vent of the hearing instrumentmay be located elsewhere (e.g. internally) and may be present in othernumbers than two (or omitted altogether). The folded substrate F-SUBcomprises a folding zone FZ extending around the folding line, where nocomponents are mounted (as indicated by the dotted line in FIG. 5a andthe vertically hatched area of the folded substrate in FIG. 5b ). Thefolding line of the substrate is indicated by dashed arrow FL. In FIG.5b , the listening device shown in FIG. 5a is enlarged to betterillustrate the features of the folded substrate as described above. Theelectrical connections (‘footprint’ FP) between the components of thefolded substrate are schematically indicated in FIGS. 5a-b . Connectingpoints CP are shown as pads electrically connected to contact points oncomponents external to the folded substrate (here a battery BAT, aspeaker SP and a microphone M are shown) by connecting wires CW.

FIGS. 6a-b show two perpendicular views of an embodiment of a foldedsubstrate according to the present disclosure. FIG. 6a shows across-sectional side view (taken along line AA′ in FIG. 6b ) of a 180°folded substrate comprising a first part F-SUB-1P and a second partF-SUB-2P separated by the folding line FL, each part being equipped withelectronic components COMP1-COMP4 mounted on both sides of therespective planar substrate parts. A folding zone FZ comprising thecurved parts of the first and second substrate parts is (symmetrically)located around the folding line FL. A folding radius R_(fold) adapted tobe larger than a critical folding radius of the substrate is indicated(as an ‘inner’ radius; it may alternatively be taken as the foldingradius of a centrally located, median plane of the substrate) togetherwith an (inner) distance TI_(FS) between opposing surfaces of the firstand second substrate parts. Here the thickness (TI_(FS)) of the foldedsubstrate (without mounted components) is equal to twice the foldingradius (R_(fold)). The folding zone FZ is, on the other hand, largerthan τ times the folding radius (R_(fold)) (in a direction perpendicularto the folding line FL, when measured in an un-folded view of the planarsubstrate, the folding line FL running perpendicular to the view of FIG.6a ). The folded substrate further comprises a component DIST adaptedfor ensuring a minimum distance (TI_(FS)) between the opposing surfacesof the folded substrate. In an embodiment, the component DIST comprisesa locking mechanism for locking the two ends of the finalized foldedsubstrate, which eases handling during manufacturing of the device. Inan embodiment, a number of such components adapted for ensuring aminimum distance between the opposing surfaces of the folded substrateare distributed on the folded substrate, e.g. located in parts of thesubstrate where no other components are easily mounted (e.g. in a wedgeformed part of the substrate). FIG. 6b shows a top view of the firstpart F-SUB-1P of the folded substrate of FIG. 6a . The upper side of thefirst part F-SUB-1P of the folded substrate (folded along folding lineFL) comprises component COMP1, e.g. a digital signal processor (e.g. SPUof FIGS. 5a-b ). The folding zone FZ of the first part F-SUB-1P of thefolded substrate is indicated in vertical hatching. The right(non-folded) edge SE of the folded substrate is shaped to fit a circularcomponent, e.g. a battery. Thereby thin, wedge-formed areas of substratepart(s) are created. The component COMP1 is electrically connected (byconductors CC1, CC2) to contact points CP located in the wedge-formedareas (e.g. for making electrical contact to an external component, e.g.a battery), thereby utilizing the available (otherwise un-useable) areabetter. The component COMP1 is connected to other components on thefolded substrate located on the second part F-SUB-2P via connectingconductors CC3, CC4 routed over the folding zone FZ. Conductors CC3, CC4may run in an intermediate layer of the substrate (e.g. in wiring of acentral, conductive layer CC in FIGS. 4a-b ) or (as shown here) on the(upper) surface of the substrate. The component COMP1 may be connectedto components on the opposite side of the first part of the foldedsubstrate (e.g. COMP2, cf. FIG. 6a ) by means of vias in the substrateelectrically connecting the two surfaces of the first part of the foldedsubstrate F-SUB-1P. Apart from the shaped edge SE, the other edges ofthe folded substrate are linear and form a rectangular outline.

The invention is defined by the features of the independent claim(s).Preferred embodiments are defined in the dependent claims. Any referencenumerals in the claims are intended to be non-limiting for their scope.

Some preferred embodiments have been shown in the foregoing, but itshould be stressed that the invention is not limited to these, but maybe embodied in other ways within the subject-matter defined in thefollowing claims.

REFERENCES

-   US 2008/0137891 A1 (Vohringer) Dec. 6, 2008-   U.S. Pat. No. 6,208,741 (INSONUS MEDICAL) 27 Mar. 2001-   WO 00/25551 A1 (BELTONE ELECTRONICS) Apr. 5, 2000-   U.S. Pat. No. 6,751,327 (INSONUS MEDICAL) 15 Jun. 2004

The invention claimed is:
 1. A hearing aid comprising: a flexiblesubstrate carrying electrical components of the hearing aid, a batteryas a separate component having a fixed outer contour; and a housing forenclosing said flexible substrate and the battery, wherein the flexiblesubstrate comprises a soldering pad soldered directly to the battery toestablish an electrical connection between at least one of theelectrical components and the battery, wherein the flexible substrateincludes an outer edge adjacent to the battery, the outer edge having acurved shape accommodating an outer contour of the battery, and whereinthe soldering pad is formed on an extension of said flexible substrateso as to fix the extension of the flexible substrate to the battery, theflexible substrate and extension being formed from a same sheet ofsubstrate, the extension being formed on another outer edge of saidflexible substrate than the outer edge adjacent to the battery.
 2. Thehearing aid according to claim 1, wherein the electrical components areincluded on a planar part of the flexible substrate.
 3. The hearing aidaccording to claim 1, wherein the flexible substrate includes a foldedsubstrate part that is folded from a planar substrate along a foldingline, thereby forming two planar parts of the substrate outside thefolded substrate part.
 4. The hearing aid according to claim 3, whereinsaid folded substrate part exhibits outer edges comprising a folded edgefollowing said folding line, and wherein the folded substrate part has ashape to provide that at least one of said outer edges of said foldedsubstrate follows the fixed outer contour of the battery.
 5. The hearingaid according to claim 1, wherein said flexible substrate is amulti-layer substrate adapted for having more than one layer of electricconductors to provide electrical connection to components on thesubstrate and/or to components external to the substrate.
 6. The hearingaid according to claim 1, wherein said flexible substrate is adapted toallow the mounting of components on both sides.
 7. The hearing aidaccording to claim 1, wherein the extension of said flexible substrateis adapted to press against a housing of an external component, when thesubstrate is in a folded state.
 8. The hearing aid device according toclaim 7, wherein a second soldering pad is formed on the extension ofsaid flexible substrate to fix the extension of the flexible substrateto the external component.
 9. A hearing aid device comprising: aflexible substrate carrying electrical components of the hearing aid, abattery as a separate component having a fixed outer contour; and ahousing for enclosing said flexible substrate and the battery, whereinthe flexible substrate comprises a soldering pad soldered directly tothe battery to establish an electrical connection between at least oneof the electrical components and the battery, wherein the soldering padis formed on an extension of said flexible substrate so as to fix theextension of the flexible substrate to the battery, the flexiblesubstrate and extension being formed from a same sheet of substrate, andwherein the flexible substrate includes a folded substrate part that isfolded from a planar substrate along a folding line, thereby forming twoplanar parts of the substrate outside the folded substrate part, and theextension extends from one edge of the one of the two planar parts, thesoldering pad being formed on the extension, and the extension beingfurther folded to accommodate the soldering pad being directly solderedto the battery.
 10. A hearing aid device comprising: a flexiblesubstrate carrying electrical components of the hearing aid, a batteryas a separate component having a fixed outer contour; and a housing forenclosing said flexible substrate and the battery, wherein the flexiblesubstrate is electrically connected to a second flexible substrateenclosed within the housing having a soldering pad soldered directly tothe battery, the second flexible substrate being provided as anextension of said flexible substrate, wherein the flexible substrateincludes a folded substrate part that is folded from a planar substratealong a folding line, thereby forming two planar parts of the substrateoutside the folded substrate part, and the second flexible substrate iselecrically connected to one edge of the one of the two planar parts,the second flexible substrate being folded to accommodate the solderingpad being directly soldered to the battery.